Efficacy of ultrasound-guided core-needle biopsy in the diagnosis of hepatic alveolar echinococcosis: a retrospective analysis

Pediatric Echinococcosis of the Liver in Austria: Clinical and Therapeutical Considerations

Echinococcosis is considered a neglected disease in most European countries. However, migratory flows of populations, long-term stays in endemic areas, uninterrupted tourism (travel to Echinococcus-endemic countries), traveling dogs and dog translocations from endemic areas, and inappropriate hygiene practices are potential factors that alarm public health officials. Identifying a cyst-like mass in the liver or lung of an individual with a travel history of likely exposure to sheepdogs in an area where the parasite Echinococcus (E.) granulosus (sive cysticus) is endemic advocates for a prompt preliminary diagnosis of cystic echinococcosis (CE), no matter the age of the affected individuals. Routine imaging techniques, including ultrasonography, computed tomography (CT) scans, and magnetic resonance imaging (MRI) scans, are used to detect cysts. After a cyst has been discovered, serologic investigations are used to confirm the diagnosis. Typically, alveolar echinococcosis (AE) is found in older individuals. Yet young people are also affected because frequent oral exploration of the environment is a regular behavior for infants and toddlers. In this review, therapeutic considerations for pediatric echinococcosis—drug-based benzimidazole therapy; AE: atypical liver resection, the resection of individual or multiple segments, a right or left hemi-hepatectomy, or an extended hemi-hepatectomy; CE: PAIR-technique, cyst excision, liver segment(s) resection (laparoscopically or conventionally)—are revised following experience in one of the most affected regions of Europe. In addition, we performed a systematic review using three databases (i.e., PubMed, EMBASE, and Scopus) to evaluate the quality of evidence in published studies on pediatric echinococcosis.

Parasite Circulating Cell-free DNA in the Blood of Alveolar Echinococcosis Patients as a Diagnostic and Treatment-Status Indicator

BACKGROUND

Alveolar echinococcosis (AE) is a serious parasitic disease caused by the larvae of Echinococcus multilocularis. It is the less common but substantially more deadly of the 2 major echinococcosis diseases that can occur globally but are concentrated in central Asia.

METHODS

We analyzed parasite circulating cell-free DNA (cfDNA) in 149 plasma samples using a DNA sequencing-based method (105 AE, 16 cystic echinococcosis, 4 liver cancer, 4 gallstones, and 20 healthy volunteers). After identifying the Echinococcus-specific cfDNA (Em-cfDNA) sequences in the samples, we determined whether Em-cfDNA could be used for AE diagnosis and as a potential indicator of the effectiveness of surgical treatment. We also examined potential associations between Em-cfDNA levels and clinical features of AE patients.

RESULTS

Our work demonstrates that varying reads of Em-cfDNA were detectable in the plasma of 100% of preoperative AE patients and that all of the non-AE patients and healthy volunteers were negative. Em-cfDNA has good sensitivity and specificity for the diagnosis of AE. We also found that Em-cfDNA levels apparently have reference value for evaluating the therapeutic efficacy of surgery interventions for AE lesions. Finally, our analysis revealed that Em-cfDNA levels can reflect meaningful information about lesion size in preoperative AE patients.

CONCLUSIONS

We demonstrate that sequencing-based monitoring of Em-cfDNA can be used in the clinic as a powerful diagnostic indicator for AE. We also note that there is a strong potential for use of this liquid-biopsy method to monitor ongoing disease status in postintervention AE patients.

Parasites of the liver - epidemiology, diagnosis and clinical management in the European context

Parasites in the liver cause significant global morbidity and mortality, as they can lead to recurrent cholangitis, cirrhosis, liver failure and cancer. Due to climate change and globalisation, their incidence is increasing, especially in Europe. The correct diagnosis of a hepatic parasite is often delayed because clinicians are unfamiliar with respective entities. Therefore, in this review, we aim to provide clinicians with a comprehensive clinical picture of hepatic parasites and to bring these neglected parasitic liver diseases to the wider attention of hepatology stakeholders in Europe and around the world.

Fast-Growing Alveolar Echinococcosis Following Lung Transplantation

Alveolar echinococcosis is a rare but life-threatening infection caused by the parasite Echinococcus multilocularis. Its natural history is characterized by a slow parasitic growth over several years. Increased incidence and shorter development delay have been reported in immune-compromised patients. We report the reactivation of aborted lesions within 12 months of lung transplantation leading to a fast-growing aggressive hepatic lesion. Timely identification of alveolar echninococcosis allowed prompt albendazole treatment and radical surgery leading to a favorable outcome 42 months after transplantation. However, close clinical, serological and radiological monitoring is required to rule out relapses in the long term. The pre-existence of aborted self-limited lesions of alveolar echinococcosis and the possibility for their atypical rapid growth in patients undergoing profound immunosuppression should be known by healthcare providers, even if working in non-endemic areas.

Comprehensive characterization of plasma cell-free Echinococcus spp. DNA in echinococcosis patients using ultra-high-throughput sequencing

Background

Echinococcosis is a life-threatening parasitic disease caused by Echinococcus spp. tapeworms with over one million people affected globally at any time. The Echinococcus spp. tapeworms in the human body release DNA to the circulatory system, which can be a biomarker for echinococcosis. Cell-free DNA (cfDNA) is widely used in medical research and has been applied in various clinical settings. As for echinococcosis, several PCR-based tests had been trialed to detect cell-free Echinococcus spp. DNA in plasma or serum, but the sensitivity was about 20% to 25%. Low sensitivity of PCR-based methods might be related to our limited understanding of the features of cell-free Echinococcus spp. DNA in plasma, including its concentration, fragment pattern and release source. In this study, we applied ultra-high-throughput sequencing to comprehensively investigate the characteristics of cell-free Echinococcus spp. DNA in plasma of echinococcosis patients.

Methodology/Principal findings

We collected plasma samples from 23 echinococcosis patients. Total plasma cfDNA was extracted and sequenced with a high-throughput sequencing platform. An average of 282 million read pairs were obtained for each plasma sample. Sequencing data were analyzed with bioinformatics workflow combined with Echinococcus spp. sequence database. After identification of cell-free Echinococcus spp. reads, we found that the cell-free Echinococcus spp. reads accounted for 1.8e-5 to 4.0e-9 of the total clean reads. Comparing fragment length distribution of cfDNA between Echinococcus spp. and humans showed that cell-free Echinococcus spp. DNA of cystic echinococcosis (CE) had a broad length range, while that of alveolar echinococcosis (AE) had an obvious peak at about 135 bp. We found that most of the cell-free Echinococcus spp. DNA reads were from the nuclear genome with an even distribution, which might indicate a random release pattern of cell-free Echinococcus spp. DNA.

Conclusions/Significance

With ultra-high-throughput sequencing technology, we analyzed the concentration, fragment length, release source, and other characteristics of cell-free Echinococcus spp. DNA in the plasma of echinococcosis patients. A better understanding of the characteristics of cell-free Echinococcus spp. DNA in plasma may facilitate their future application as a biomarker for diagnosis.

Echinococcosis is one of the most neglected tropical diseases caused by the metacestodes of Echinococcus spp. tapeworms, which affect both humans and livestock. Plasma cell-free DNA (cfDNA) consists of nucleic acid fragments found extracellularly and may contain DNA released from the parasites. Research shows that a variety of parasites can be detected from plasma cfDNA. Cell-free Echinococcus spp. DNA in plasma or serum had been tested with PCR-based methods, but these PCR methods had low sensitivity ranged from 20% to 25%. Low sensitivity may be due to our limited understanding of cell-free Echinococcus spp. DNA in plasma. Here, we take advantage of high-throughput sequencing to get a comprehensive characterization of cell-free Echinococcus spp. DNA. Our results showed that with high-throughput sequencing we could detect cell-free Echinococcus spp. DNA in all samples, though at a very low level. Based on the sequencing data, we found that cell-free Echinococcus spp. DNA in plasma had a different fragment length distribution to cell-free human DNA, and fragment length distribution of cell-free Echinococcus spp. DNA is also different between cystic echinococcosis (CE) and alveolar echinococcosis (AE). The sequencing data can also help trace the release source of cell-free Echinococcus spp. DNA from the genome. According to the mapping results of cell-free Echinococcus spp. DNA reads, we found that most of them were from the nuclear genome rather than the mitochondrial genome, and their release position showed an even distribution on the genome. These characteristics of cell-free Echinococcus spp. DNA in echinococcosis patients’ plasma could facilitate their future application in research or clinical settings.

Echinococcosis: Advances in the 21st Century

Echinococcosis is a zoonosis caused by cestodes of the genus Echinococcus (family Taeniidae). This serious and near-cosmopolitan disease continues to be a significant public health issue, with western China being the area of highest endemicity for both the cystic (CE) and alveolar (AE) forms of echinococcosis. Considerable advances have been made in the 21st century on the genetics, genomics, and molecular epidemiology of the causative parasites, on diagnostic tools, and on treatment techniques and control strategies, including the development and deployment of vaccines. In terms of surgery, new procedures have superseded traditional techniques, and total cystectomy in CE, ex vivo resection with autotransplantation in AE, and percutaneous and perendoscopic procedures in both diseases have improved treatment efficacy and the quality of life of patients. In this review, we summarize recent progress on the biology, epidemiology, diagnosis, management, control, and prevention of CE and AE. Currently there is no alternative drug to albendazole to treat echinococcosis, and new compounds are required urgently. Recently acquired genomic and proteomic information can provide a platform for improving diagnosis and for finding new drug and vaccine targets, with direct impact in the future on the control of echinococcosis, which continues to be a global challenge.

Hepatic alveolar hydatid disease (Echinococcus multilocularis), a mimic of liver malignancy: a review for the radiologist in non-endemic areas

Alveolar hydatid disease or alveolar echinococcosis (AE) is caused by the parasite Echinococcus multilocularis and is increasingly seen as an imported disease in non-endemic areas such as the UK. It is rare compared to cystic echinococcosis (CE), but like CE commonly affects the liver. AE does have imaging features that can aid in diagnosis, but is often initially misdiagnosed as liver malignancy. It is usually fatal if untreated, underscoring the importance of early diagnosis. This review highlights the role of imaging in AE diagnosis with the broader objective of increasing radiologists' awareness of this unusual, but increasingly prevalent disease.

Case Report: Role of Interventional Radiology in the Management of Patients with Alveolar Echinococcus: Successful Management of Three Cases

Alveolar echinococcus (AE) is an infestation by Echinococcus multilocularis. Partial hepatectomy or liver transplantation is the first choice of treatment. However, the disease is usually diagnosed at an unresectable stage. In those cases, invasion of the bile ducts and vessels, and necrosis in the center of the lesion lead to severe complications, such as cholangitis and liver abscesses. Palliative surgery has been reported to not offer advantages in management, and percutaneous and endoscopic interventions have become more prominent in management. In this case series, outcomes in three cases with unresectable AE were reported. In one of the cases, interventional procedures were used to manage the complications after surgery. In the second case, the cystic component was aspirated to decrease the size before the surgery and in the third case, it was used to drain biliary tree and no surgery was done.

Large-scale evaluation of a rapid diagnostic test for human cystic echinococcosis

Cystic echinococcosis (CE) is a neglected zoonotic disease, diagnosed through clinical findings, imaging techniques, and serology, for which many serological tests are available. Here we report a rapid unit assay, the immunochromatographic VIRapid® HYDATIDOSIS test (Vircell, Granada, Spain), potentially suitable for laboratories in low-prevalence or poorly equipped areas. This test was evaluated with a large retrospective cohort (224 sera), including patients suffering from CE or from other parasitic or liver diseases. The test was also assessed in routine conditions with a prospective cohort (115 sera) in areas where both cystic and alveolar echinococcoses have been diagnosed. Its performance (in terms of sensitivity, specificity, and both positive and negative likelihood ratios) was similar to an ELISA based on a crude antigen. Our study shows that this test performs adequately in the diagnostic process, when used with caution, especially regarding cross-reactivity with other parasitic diseases.